It’s usually not just due to losing muscle mass over time (more on that later). "It's multifactorial," says Fatima Stanford, MD, MPH, obesity medicine physician scientist at Massachusetts General Hospital and Harvard Medical School. Numerous factors can sneak up on you and help you gain or hold onto weight, including your lifestyle, your food, your biology, and your sleep habits. The good news in that is that there are also numerous ways to tackle getting your weight to where you want it—you don't have to force yourself into one approach, and you get to choose what works for you.
Sarah Mirkin, RDN, author of Fill Your Plate Lose the Weight, recommends 20 to 30 grams of protein per meal. "It’s important to take in that amount of protein at all your meals, and ideally include high protein snacks as well," Mirkin says. "This helps to prevent lean muscle protein breakdown that decreases muscle mass percentage, increases fat percentage, and slows the metabolic rate. Muscle burns calories. Fat doesn’t."
Yeah, you've probs heard that diet tip before—as it's wise for anyone trying to lose weight. Fried foods contain a whole lot of fat and contribute to weight gain—simple as that. But again, in your 40s, you deal with natural physiological changes that make it *even* tougher to shed excess weight, so overdoing it on fried foods has larger consequences. "A 20 year old can get away with eating empty calorie meals. A 40 year old usually cannot on a semi regular basis," Mirkin points out. "Until we are age 20, [our] bodies are building muscle. After age 20, it stops."
"One of the reasons that it's difficult to lose weight in your 40s is that you are beginning to lose muscle mass, so the composition of your body tissue changes," explains Keri Peterson, MD, Women's Health advisor. "Having higher muscle mass raises your metabolism, so your body burns more calories." So when you're dealing with the opposite—less muscle mass—that means a slower metabolism. Argh.
Between desk jobs, commutes, and family activities, many 40-somethings don’t have a lot of free time to work out. But it’s important -- for your weight and your overall health -- to fit in at least 2 1/2 hours of moderate physical activity (like brisk walking or light yard work) every week. Pencil times in to your calendar, and make them a priority.